Following the rapid development and change of information technologies and sociocultural environments, public libraries are recently facing demand for various changes regarding their traditional functions and roles. They need to make efforts to understand accurately the changing factors of their surrounding environments and their resulting job changes so that they can make active responses to the changes of the times. The purposes of this study are to diagnose changing situations in the current surrounding environments and job content of public libraries and propose a basic direction for them to figure out and react to the causes of their core change content. For these purposes, the study 1) examined literature and previous studies on the surrounding environments and job factors of public libraries, 2) reviewed current job states and change cases in major criteria and standards, legislations, institutions, and policies about public libraries, and finally 3) identified the factors of their surrounding environments and job changes, tested their validity in the delphi method.